The present invention generally relates to power hand tools and, more particularly, to plunge-type routers.
Plunge-type routers are used to cut a variety of shapes in work pieces made of wood and other materials, with the shapes being determined by the kind and shape of router bits used, the depth of cut of the bit and the path of travel by the router bit relative to the work piece. A plunge router is constructed to move the router bit toward and away from the work piece when the router is being operated by hand. The depth of cut of the router bit is typically determined by an adjustable depth stop system which may or may not include means for locking the router in its plunged position.
During operation, the plunge router may be supported on the work piece with the bit retracted and placed in the desired position so that when it is turned on and plunged, the router bit advances into the work piece where the operator moves it relative to the work piece to complete the desired routing operation. To do the plunging operation, the operator must exert a downward force on the head assembly, generally by pressing on handles attached to it, to move the router bit into contact with the work piece. The head assembly is typically biased to automatically retract the router bit from the work piece when the downward force imparted by the operator is removed.
Plunge routers generally include a plunge adjustment mechanism that enables the operator to control the distance the router bit can move toward the work piece and thereby determine its depth of cut. As is well known to those who have used plunge type routers, the adjustment of the stop system must be carefully done to achieve the desired depth of cut. Because the type and size of various router bits are very different, it is prudent if not absolutely necessary to recalibrate or reset the adjustment means after any manipulation of the router bit to insure that it has been accurately set to achieve the desired depth of cut. There are many other devices that attempt to accurately set the depth adjustable stop to provide an accurate depth of cut including adjustable rods, scales with indicators, micrometer type adjusters and other systems. Such adjustable stop mechanisms in the prior art are generally hand manipulated and some may have a printed scale or other indicia located on the mechanism for use in providing a specified depth of cut. However, it is still necessary for users to carefully measure the depth of cut in one way or another to insure that the desired cut will be made. In this regard, it is often common practice to perform a test cut on a scrap piece and actually measure the result and to iteratively adjust the stop mechanism until the proper result is achieved.
A plunge-type router is disclosed which is adapted for either free hand use or mounted beneath a router table. The router has a base and a head assembly with the base being adjustable relative to the head assembly by an adjusting mechanism. The plunge router of the present invention includes an electronic control system with a digital display and control functionality that enables the router to accurately determine a baseline or zero position for a router bit installed in the router and permits the user to input a depth of cut value or other predetermined command. The system then automatically adjusts a motorized depth adjustment mechanism to achieve the appropriate position. The electronic control system enables the storage of multiple depth settings as well as multiple step or macro operations. In this regard, macros may be run to provide incremental cutting necessary for performing multiple passes to achieve a relatively deep depth of cut.
The present invention may include as an alternative embodiment a supplemental electronic control panel that can enable a user to install the plunger router in a router table and yet have a control panel clearly visible to the user even though the router is mounted underneath the table surface in an inverted position. The electronic system also enables the choice of either metric or English units of measure. The speed of operation of the main drive motor can be provided on the display, as well as an identification of a macro number or other information relating to the particular operation that is being carried out. In the event of multiple step macro operation, stepping between progressively deeper depths of cut may be manually triggered by the user on the control panel and displayed thereon.